A casement or an awning window generally refers to a sash that is attached to its frame by one or more hinges. The hinges can be located on any side of the sash and the frame though generally not on the lower edge of the sash and frame. In general, a casement window rotates along a horizontal plane (the hinges of a casement window defining a vertical rotation axis), while an awning window rotates along a vertical plane (the hinges of an awning window defining a horizontal rotation axis). Most casement and awning windows which employ the use of a crank lever or cam handle operator open outwardly so as not to interfere with the operator of the window.
An advantage of many casement and awning windows is that substantially the full window opening can be exposed without requiring the removal of the window from the frame. In contrast, for example only half of the opening of a double-hung window can be exposed by raising the lower sash or lowering the upper sash. The sashes of double hung or horizontally sliding windows must be completely removed from the frame to expose the entire window opening.
The ability of casement windows to be opened so as to fully expose the window opening also can be disadvantageous, however. In certain instances, some casement and awning windows can be opened wide enough that individuals or large objects can fit through the opening.
Recent modifications to building codes and window safety standards have been implemented in an effort to prevent or deter injuries to individuals, particularly children, from falling out of open windows. For example, proposed changes to the International Building Code (“IBC”) and the International Residential Code (“IRC”) aimed at child window safety require that certain windows be fitted with window opening control devices. Such window opening control devices may limit the ability of casement windows to be opened beyond a certain point. This limited opening is typically defined by the maximum diameter of a hypothetical sphere that is allowed to pass through the window opening when the sash of the window is opened to the limited position. For example, current CTC safety standards stipulate that a 4-inch diameter sphere shall not pass the opening of a casement or awning window when the opening is in its largest opened position.
At times, there may be a need to override the window opening limit device so that the casement window can be opened beyond the limited position. In particular, it may be necessary to fully open the window. During an emergency, for example, an egress casement window opening may provide an escape route for individuals or an access route for emergency personnel. Accordingly, building and residential codes may require window opening limit devices to be equipped with a release mechanism. The need may also exist that such window opening limit devices be operable without keys, tools, or special knowledge and deter or prevent operation by young children.
Unless the window opening limit device is reengaged once released, casement windows could potentially be operated so as to allow the window opening to be fully exposed. Subsequent users, for example, may not realize that the window is equipped with such a device or that the device has been released. Therefore, there exists a need for window opening limit devices to possess the capability to be self re-engaging even if a user does not intend to reengage the device through the user's actions.
The cost of replacing windows is often significant. Therefore, there also exists a need for a window opening limit device that can be installed onto existing casement windows.
In addition, existing casement and awning windows are not uniform in size. In fact, the size of casement and awning windows can vary substantially. Therefore, there exists a further need for a window opening limit device that can be installed onto existing casement or awning windows regardless of the dimensions of the window frame.